Hard disks and the good old days

Thinking about this post (does LaCie actually manufacture disks? do they actually make a one-platter 1-TB disk, or is their external unit a two-disk combo?) brought back memories of the first hard disk I had direct access to.

Late 1970s. UC Berkeley, Doe Library. We had a local area network of sorts, with three or four semi-intelligent terminals running off one central unit, to support data entry–for serials checkin, I think. I wrote the 24-hour oversight system. Once a week, we gathered up all the data to transmit to the data processing center we were using (via tape, as I remember). The data was gathered on a removable disk cartridge.

The system worked reasonably well (and slight glitches in the weekly process were key to my personal life: That’s how I met my wife). Given the technology involved, it’s amazing that it worked at all. Consider:

  • The central unit was a Datapoint “minicomputer,” with a Z80A CPU running at 2MHz, and with (I believe) 128K of RAM. If you know the history of micros, the Z80A was an 8-bit chip, somewhat comparable to the Intel 8088. The operating system and primary programming environment was Databus, a remarkably robust OS with a flexible database system built in. Not terribly fast, to be sure, but a whole lot better than you’d expect from such a primitive CPU.
  • The removable hard disk held 10 megabytes. That’s mega, not giga. It was a 14″ device, and I’m pretty sure it had multiple platters within the case. I don’t remember the replacement cost, but it was high enough to encourage us to take extremely good care of it.
  • If I recall correctly–and this was almost 30 years ago, so that’s unlikely–we actually ran it as a straight multiterminal time-sharing system, but we could have run a LAN. If we had, the LAN would have been ARCNet, not Ethernet. ARCNet was a token network and worked extremely well particularly given the limited processing power and bandwidth at the time (and was used in thousands of back offices in businesses, frequently without the business’s IT department even knowing about it).

Ten megabytes on a multiplatter 14″ drive. Right now, you can get 750 gigabytes–75,000 times as much storage–on a 3.75″ single-platter drive. Running several times as fast, and probably with 8 megabytes RAM as a buffer. For a few hundred bucks.

Do I look back longingly at the Datapoint days? Not a chance. You could do remarkable things–for the time and the power–with Databus, but it still had some of the characteristics of a chess-playing bear.

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